1. Field of the Invention
The present invention relates to a glass run mounted on a vehicle door.
2. Related Art
A vehicle door of an automobile or the like is provided with a glass run that seals a peripheral edge part of a door glass moved up and down. The glass run includes a cross-sectionally substantially-U-shaped body portion which has a base wall part and a pair of sidewall parts respectively extending from opposite ends of the base wall part, and also includes a pair of seal lips inwardly extending into the body portion from substantially ends of both the sidewall parts of the body portion, respectively, to seal the door glass.
Generally, the glass run is constituted by a solid elastic material having relatively high stiffness. Consequently, there is a fear of occurrence of a gap between the glass run and a door frame at the mounting of the glass run due to tolerance at the manufacture of the glass run. Accordingly, in recent years, to prevent occurrence of the gap between the glass run and the door frame, some conventional glass runs have been configured so that lip portions adapted to abut against the door frame are formed in an extended condition at the side of a door-frame facing surface of a bottom wall portion of the glass run (see, for example, JP-A-2003-165340).
However, although the lip portions of the conventional glass runs are sufficient to prevent water from infiltrating into a vehicle interior, such lip portions are insufficient for sound insulation to prevent external ambient noises and disturbing noises from infiltrating into the vehicle interior.
To solve this problem, it has been assumed to configure a vehicle so that a sponge elastic material layer put into elastic constant with a wall portion of a door frame is provided in the entirety of the cross-sectionally substantially-U-shaped outer peripheral part of the body portion to fill a relatively wider range of the gap between the glass run and the door flame therewith, as compared with the conventional case of filling the gap with the lip portions.
However, in a case where the sponge elastic material layer is provided in the entirety of the cross-sectionally substantially-U-shaped outer peripheral part of the body portion, as described above, the sponge elastic material layer does not slide along a wall portion of the door frame when the glass run is assembled to the vehicle door. Thus, the assembling of the glass run to the vehicle door by sliding the body portion therealong and pressing the body portion into an inner part of the door frame, similarly to the case of the glass run made only of the solid elastic material cannot be performed. There is a fear of reduction in assemblability. Consequently, also, there is a fear that during the assembly of the vehicle, the sponge elastic material layer ma be caught in the wall portion of the door frame, and that a caught part of this layer may break.
Also, in a case where the door glass is put into a fully closed position, there is a fear of generation of a sound of a thud, i.e., what is called a thudding sound due to impact caused when the door glass abuts against the top side portion of the glass run. In recent years, to reduce such a collision noise, some conventional glass runs have been configured so that the bottom wall portion has a buffer part. Such a glass run is configured to allow the top edge portion of the door glass to abut against the bottom wall portion of the glass run through the buffer part thereby to lessen the impact. Thus, the collision sound is reduced.
However, generally, the glass run is made of a relatively hard solid elastic material, as described above. Therefore, the conventional buffer part is insufficient for lessening the impact at the abutment of the buffer part against the door glass.
Also, conventionally, the generation of collision sounds is suppressed due to the structural properties of the glass run (or buffer part). Accordingly, in a case where a position, at which the door glass actually abuts against the bottom wall portion of the glass run, is deviated toward the exterior of a vehicle exterior, the effect of lessening the impact may be insufficiently obtained, depending upon a place of the door glass, against which the bottom wall portion of the glass run abuts.